2.2.9. ADO updates the record

发布时间 :2025-10-25 12:23:20 UTC      

We can use SQL’s UPDATE to update a record in the database table.

Update records in database tables

We want to update Northwind in the data Customers a record of a table. First we need to create a table to list Customers all records.

<html>
<body>
<%
set conn=Server.CreateObject("ADODB.Connection")
conn.Provider="Microsoft.Jet.OLEDB.4.0"
conn.Open "c:/webdata/northwind.mdb"
set rs=Server.CreateObject("ADODB.Recordset")
rs.open "SELECT \* FROM customers",conn
%>
<h2>List Database</h2>
<table border="1" width="100%">
<tr>
<%
for each x in rs.Fields
  response.write("<th>" & ucase(x.name) & "</th>")
next
%>
</tr>
<% do until rs.EOF %>
<tr>
<form method="post" action="demo_update.asp">
<%
for each x in rs.Fields
  if lcase(x.name)="customerid" then%>
    <td>
    <input type="submit" name="customerID" value="<%=x.value%>">
    </td>
  <%else%>
    <td><%Response.Write(x.value)%></td>
  <%end if
next
%>
</form>
<%rs.MoveNext%>
</tr>
<%
loop
conn.close
%>
</table>
</body>
</html>

If the user clicks the button in the “customerID” column, a new file “demo_update.asp” opens. This file contains the source code to create input fields based on the fields recorded in the database, as well as an “update button” to save changes:

<html>
<body>
<h2>Update Record</h2>
<%
set conn=Server.CreateObject("ADODB.Connection")
conn.Provider="Microsoft.Jet.OLEDB.4.0"
conn.Open "c:/webdata/northwind.mdb"
cid=Request.Form("customerID")
if Request.form("companyname")="" then
  set rs=Server.CreateObject("ADODB.Recordset")
  rs.open "SELECT \* FROM customers WHERE customerID='" & cid & "'",conn
  %>
  <form method="post" action="demo_update.asp">
  <table>
  <%for each x in rs.Fields%>
  <tr>
  <td><%=x.name%></td>
  <td><input name="<%=x.name%>" value="<%=x.value%>"></td>
  <%next%>
  </tr>
  </table>
  <br><br>
  <input type="submit" value="Update record">
  </form>
<%
else
  sql="UPDATE customers SET "
  sql=sql & "companyname='" & Request.Form("companyname") & "',"
  sql=sql & "contactname='" & Request.Form("contactname") & "',"
  sql=sql & "address='" & Request.Form("address") & "',"
  sql=sql & "city='" & Request.Form("city") & "',"
  sql=sql & "postalcode='" & Request.Form("postalcode") & "',"
  sql=sql & "country='" & Request.Form("country") & "'"
  sql=sql & " WHERE customerID='" & cid & "'"
  on error resume next
  conn.Execute sql
  if err<>0 then
    response.write("No update permissions!")
  else
    response.write("Record " & cid & " was updated!")
  end if
end if
conn.close
%>
</body>
</html>

Principles, Technologies, and Methods of Geographic Information Systems  102

In recent years, Geographic Information Systems (GIS) have undergone rapid development in both theoretical and practical dimensions. GIS has been widely applied for modeling and decision-making support across various fields such as urban management, regional planning, and environmental remediation, establishing geographic information as a vital component of the information era. The introduction of the “Digital Earth” concept has further accelerated the advancement of GIS, which serves as its technical foundation. Concurrently, scholars have been dedicated to theoretical research in areas like spatial cognition, spatial data uncertainty, and the formalization of spatial relationships. This reflects the dual nature of GIS as both an applied technology and an academic discipline, with the two aspects forming a mutually reinforcing cycle of progress.